Potentially hazardous leak after Melbourne truck overturns

A truck containing 200 drums of liquid has overturned in Melbourne, causing an unidentified substance to leak and triggering fears a hazardous materials emergency could be at foot.

Scientific advisors are on-site at the Campbellfield accident to identify the liquid after emergency crews identified 10 leaking drums on Saturday morning.

Environmental authorities including the Environment Protection Authority (EPA) and Melbourne Water have been notified, a Hazmat response initiated, and 28 firefighters with four pumpers are ready for action at the Barry Road site.

The area has been blocked off to traffic.

Environmental authorities are assessing if materials leaking from drums are hazardous after a truck overturned in Campbellfield. (9News)

The incident comes amid ongoing investigations into a factory fire at a nearby waste processing plant at Campbellfield in April.